Fire alarm devices such as audible horns (audible/visible or A/V), loudspeakers (speaker/visible or S/V) and visible strobes (visible only or V/O), are referred to as “notification appliances.” Typically, a fire alarm control panel (FACP) drives these devices over one or more “notification appliance circuits” (NACs). The strobes are required, for example, as an alert for the hearing-impaired, or for those in a high noise environment.
A strobe is typically made up of a high-intensity Xenon flash tube, a reflector assembly, a transparent protective dome, an electronic control circuit, a terminal block to connect the device to the NAC and a housing to install the device to a wall or ceiling.
The strobe is a notification device designed to disperse its light output in a hemispherical pattern. The light distribution must meet stringent specification for UL approval. The color of the light output may indicate different types of notification. For example, a white light output may indicate a fire emergency, whereas an amber light output may indicate an intruder on the premises (or a similar type of mass notification). Typically, the same type of strobe is used to indicate the different types of notification, with the exception of the type of lens placed on the strobe. In particular, when a strobe is designated to output white light, a clear lens is placed on the housing of the strobe. When a strobe is designated to output amber light, an amber colored lens is placed on the housing of the strobe.
When a premises has both a fire alarm and a mass notification system, the two types of strobes are installed in every location—i.e., one strobe that outputs white light and a second strobe that outputs amber light. Careful planning is required for installation so that the two strobes, which are typically mounted next to one another, do not interfere with each other. One method for proper installation of the two strobes is to use special mounting assemblies, which keep the different strobes at different elevations relative to one another. However, these mounting assemblies are rather large and cumbersome. Accordingly, a need exists for outputting both white light and amber light from strobes that is simple in design and operation.